Resilient tilting lock for outboard motors



R. N. KIRCHER ET AL 2,646,238

RESILIENT TILTING LOCK FOR OUTBOARD MOTORS 4 Sheets-Sheet 1 July 21, 1253 Filed June 8, 1950 INVEI 'TORS RALFH N. Kmcnsn Run-cam: C. HEIBNLR BYWILFORD B. Gunmen- July 21, 1953 R. N. KIflcHER ET AL ,6 5,

RESILIENT TILTING LOCK FOR OUTBOARD MOTORS Filed June 8, 1950 4 Sheets-Shee t 2 4 I56 I58 8 I64 INVENTORS RALPH N. KIRCHER F a. I o Rim-ammo C.H|oun y WILFQRD B. Burma-T ATTORNEY y 1353 R. N. KIRCHER ET AL 2,646,238

RESILIENT TILTING LOCK FOR OUTBOARD MOTORS 4 Sheets-Sheet 3 Filed June 8, 1950 INVENTORS RALPH N. Kmcuan '74 kguam: C-HEIDNER y WILFORD 5.6URKETI' W 0 AT-ronuzvs July 21, 1953 R. N. KIRCHER ETAL RESILIENT TILTING LOCK FOR OUTBOARD MOTORS 4 Sheets-Sheet 4 Filed June 8, 1950 I INVENTORS Emma N. Kmcuzn Rum-MRO C- Hcwmnn y Wmroao 6. Gunmen- Patented July 21, 1953 UNITED s PATE T I OFFICE RESILIENT TILTING LOCK i on oUTBoARn l 7 TORS Ralph'N. Kircher-,.:West Bend, and Richard C. Heidner. and Wilford B. Burkett, Hartford, Wis., assignors to West Bend Aluminum (30., West Bend, Wis., a corporation of Wisconsin Application June 8,1950, Serial No. 166,808

1 I This invention relates to improvements in outboard motors and particularlyto a mounting for such motors which resiliently resists rear ward upward tilting f the lower-legs of such mo- 11 Claims. 01. 248-4 a predetermined amount designed for safe sternward 'movement. There are many mechanical tors relative to the boat during reversing of propeller thrust and freely permits such tilting when not in operation.-

Outboard motors now have boat mountings which permit the lower leg of the motor to be manually tilted-rearwardly to raise the propeller out of the water'or to allow the under-' water leg to swing rearwardly if it strikes an obstruction-while inoper'ation. Outboard m0- tors so mounted, if turned about a vertical axis to reverse the direction ofthe propellerthrust, or if their propellers are reversed by reversing reversed for the purpose of: stopping or backing up the boat. V i

Another object of this invention is'to provide a mounting for an outboard motor which automatically tilts the angle of reverse thrust so that it is directed downwardly to lift the stern of the boat when the power exceeds that necessary to. safely back upthe boat.

A still further object of this invention is ,to' provide a mounting for an outboard motorwhich will automatically prevent the generation of excessive sternward speed of the boat.

A stil1:further object is to provide a. mounting,

for an outboard motor which will prevent the underwater leg thereof from tilting rearwardly and upwardly as the speed ofthe motor is varied during the forward propulsion of the boat.

A still further object of the invention is to provide a mounting for an outboard motor which will automatically produce an audible safety l:-

warning when the engine, while the propeller is in reverse thrust motion, generates power in ex cess of that for safely operating a boat sternward.

These objects are obtained by providing in a mounting, which permits the lower end of the outward motortov tilt rearwardly and upwardly, a resilient member which resists such tilting and only permits it to take place whenever the force of the reverse thrust ofthe propeller exceeds amount is'approximately. reached, and should variations by which the force of #the resilient member may be applied to the motor. sential characteristic of this'invention isv that the resilient member permit upward and rearward tilting to commence when the force reverse thrust ofthe propeller approaches a-predetermined safe amount. When this safe more and more power be applied,.the propeller end of the motor will gradually tilt rearwardly and upwardly thus causing the angle of pro-' peller thrust'to. lift the stern of the boat. and. thus prevent submerging. If the power isfur th'er increasedwithattendant increase in propeller thrust, the rearward angle will eventually be such that the exhaust nozzle will break above the surface of the water causing a loud exhaust 3 noise which serves to Warn the operator.

heed is paid to this. warning andthepower and associated thrust are furtherincrea'sed, the pro peller will raise'tothe surface of the water creating excessive splashing which serves as an ad ditionalaudible and physical warning and atthe same time reduces the rearward component' of. thrust.v It is desirable that the resilient member offeriinitial resistance againstrearward and upward tilting even during forward thrust.

.Such force will prevent the outboard motor from rearwardly tilting due to speed changes occurring during the forward'operation of the boat. When the motor is not in operation,it can be easily tilted rearwardlyupwardly by providing a latching device between the resilient member and the -motor or between such member and the'boatt; When-such latch is unfastened themotor may,

be swung rearwardly and upwardly with respect to the boat without distorting the resilient member. When the latch is fastened the resilient member is again brought into operation tore:

si'st such tilting. The latch is preferably designed to automatically look as the motor is f 7 moved into normal untilted position.

The novel features, which are considered char-' acteristic of the invention, are set forth with particularity in the appended claims. The in vention itself, however, both as to its organization and its method of operation, together with additionalobjects and advantages thereof, will best be understood from the following 'd'escription of specific embodiments whenread in connectlon with the accompanying drawings, in

which:

.. Fig. 7.111s aside yiewflofan "outboard motor The ese.

'when the automatic lock .is released and the motor is locked in its farthest upward. tilted position;

Fig. 6 is a fragmentary view of the mountingwhen the automatic lock is locked and the motor is partially tilted against the resilience of the anti-tilt spring;

Fig. 7 is a fragmentary view partly in section and. partly in plan of a modification of the invention;

Fig. 8 is a fragmentary enlarged sectional. view taken on line 8-8 of Fig. '7';

Fig. 9 is a fragmentary sectional. view taken on. line 9--9 of Fig. 8;, and

Fig. 10 is a fragmentary sectional view similar to the view of Fig. 8 and illustrating a. still further modification of the invention.

Referring to the drawings by reference numerals, the outboard motor, shown schematically in. Fig. 1, is of standard; design. It has a leg l-fl at the. lower end on. which is mounted the propeller 12. At the topv of .such. leg within a cover 14 there is an engine. (not shown) for supplying power to the. propeller. A tiller I6 is used to. turn the motor and steer the boat and. its handle controls the. operation. of the engine. The motor. also has a reversing. mechanism. by which the direction of thrust. of the propeller .12 may be changed from forward. to reverse. There is no. interlock between the reversingv mechanism and the engine. control- It is therefore possible for the. operator to..cause the engine to develop its. full, power whilethe propeller is producingreverse thrust..-

The outboard motor is. mounted to the transom. l8 or other part, of a. boat by a. mounting which includes a swivel bracket 22: and a stern bracket 46- connected thereto by a pivotal: connection 34-. motor so that it may be turned. about an. upright axis for steering. means by which it is clamped to the transom. The pivoting of the swivel'bracketrelative to the stern bracket permits the motor to be tilted rearwardly and" upwardly as illustrated in Fig. 1. As iscustomary in this type of mounting, a thrust receiving member 60' pla ceable in a variety of positions receives the forward thrust from the swivel bracket and thus. transmits power to the boat while maintaining the outboard motor at the desired angle with respect to the transom of the boat. For best forward operation the motor is in a. substantially vertical. position and the forward thrust of the propeller is at an angle slightly down from the. horizontal.

In the modification of the invention of Figs. 1 to 6, an anti-tilting mechanism. (including a coiled axially loaded tension spring 14) is p:- sitioned between the swivel bracket 22 and the stern bracket. 46- and. resiliently maintains those members in the position shown in Fig. 2. and resists. the. rearward. tilting. of the swivel bracket The swivel bracket. 22 holds the.

The: stern bracket. 46 has except when sufficient force is applied to overcome the force of the spring. I

Proceeding now to the detailed description of the swivel bracket 22, it has a cylindrical bearing 24 in which is rotatably received a hollow king pin 26 by which the motor is carried so as to rotate about an upright axis to accomplish steering of the boat. A drive shaft- 28 from the engine (see Fig. 4) extends through the hollow king pin. The swivel bracket has a top 30 connecting spaced sides 36 and 38 in which are located bearings 32 (see Fig. 3) which rotatably receive the horizontal pivot 34 providing thepivotal connection between the swivel bracket and stern bracket. The sides 36 and 38 project forwardly from the cylindrical bearing 24 and define a recess therebetween which receives the anti-tilt mechanism. Trunnions 40, one on each of the inner surfaces of the sides 36 and 38 (only one shown, see Fig. 3), receive and hold an anchor pin 42 by which the upper endof the anti-tilt spring is secured to the swivel bracket. It is also advantageous to provide the swivel bracket with abutments 44 located near the bottom of the bearing 24 in the recess. be.- tween the sides. These abutments engage the lower end of the anti-tilt spring. bracket 66 to arrest it in its fully retracted position. within such recess.

The stern bracket 46 has a frontwall 48 which interconnects twov parallel legs 50 and 52 spaced so. as to be in overlapping relationship with: the sides 36 and. 38. At. the top ofthese legs near the; juncture with the front wall are openings for mounting the horizontal pivot. 34; As is. shown in Fig. 3, the adjacent edges. of the sides 36 and 38 and legs: .50: and 52 are provided. with raised bearing surfaces 54: which provide a sliding: guide between. the swivel. bracket and the stern bracket during tilting.- motion therebetween. A cross brace 56 preferably extends; between. the lower portions of the legs 50 and 52: to strengthen them" and provide a bearing. area for the transom l-S. A pairof rearwardly projecting: horns 58 with spaced openings therein receive the adjustablethrust pin 60 in the selected proper positiondepending upon the slope of the transom I13 with respect to the vertical. The: front wall 48 has threaded-openings.with hand. screw clamps 62. of customary design therein to engage the transom. With. the stem. bracket. 46 mounted as shown,. the swivel; bracket 22 may be tilted rearwardly and upwardly from. the substantially vertical position shown. in Figs. land 2 to its upper limitshown. in Fig. 5.. Such upper limit is determined by the abutment between a raised bead 63 on the. swivel; bracket andthe rear' edge of the; front Wall 48 on the stern bracket. In order to hold the swivel bracket in the extreme raised position shown in Fig... 5:, a snap lock pin 64 is mounted in: the leg. 59. and is spring-biased so that it will: project under the side: 3'5 6%.

diagrammatically indicated in: the broken. lines of Fig. 5) when the swivel bracket is inv the extreme raised position. To lower the swivel bracket 22- from. such position. it is: only necessary: to: pull the knob of the lock 542 outwardly and withdraw. its inner: end from beneath. the edge of such side. The forward thrust position. of the swivel bracket is: determined by the engagement. between the forward: edges ofthe sides 35 and: 38 and the. adjustable thrust pin 86'. This pin is placed in such: of the openings in the. horns 58 as will cause the drive: shaft of the motor' to be in substantially verticai position I when the stern bracket isolamped to'the transomIB, a

I The anti-tilt mechanism which isincorporated within the swivel bracketand stern bracket consists of a springbracket fiiihaving spaced sides 68 and T8 shaped as shown in Figs.,2 to 6, inclusive, joined by a body 72 at the forward edges of such sides; The bracket v6G is pivoted atthetop of such sides to the horizontal pivot 34 or to pivotal interconnection between the stern brack-. et and swivel bracket and fits within the recess ofswivel bracket 2; in itsat rest-position. The

initially tends to hold the spring bracket tightly 1 within the recess in .the swivel bracket, as shown in Figs. 2 and 5. The advantage of this is that the motor is held in itsnormal upright'position under tension and hence will, not tip rearwardly as the result of varying changes in. speed as it is driving the boat. 1 Both the a'nchor pins 42 and 715 are held against longitudinal displacement by cotter .pins placed therein and abutting against adjacent sides of 'themember in which the pins are mounted. Such anchor pins may also be provided with a circumferential groovein which the eye on each end of the spring I4 fits to keep that spring properly centered.

' When the lower end of thespring bracket 65 is attached to the 'stern'bra'cketit cannot rotate with the swivel bracket. Hence as the swivel bracket tilts *rearwardly and upwardly with respect to the sternbracket the sprin 'l i will be elongated and resiliently resist such tilting. Such lower-end is only temporarily secured and may be released from the stern bracket-so that the motormay be freely tilted upwardly 're'arwardly to its raised position in Fig. 5 without elongating the spring I4. The automatic lock for this purpose includes a latch I8 having rearwardly extending spaced legs- 80 and 82" which 'pass through slots in the body I2 and are pivoted re spectively by rivets 84 and 86 to the sides 68 and I0. Thelower edge of-the legs have U notches 83 adapted to engage-with thethrust pin "60 when the swivelbracket is moved into its normal position as shown in Figs. 1 and 2; The legsBU and 82are joined by a connecting plate 90 which has a threaded hole therein toholda screw and washer c1amp92. This clamp engages the end of a .fiexible Wire 94 which passes upwardly through an'opening in the wall 48 and along its inner surface .to the top thereof. The wire 94 projects from the-wall 48 at the horizontal pivot 34 and has its upper end secured to a guide sleeve 96 projecting through an-opening in the front wall i8.- The outer end of such sleeve has a hand-gripping knob 98 secured thereto.- The latch I3 is continuallynrged Idownwardly to latching position by a coil spring I06 extending between the leg 80 andv the lower end of the side 58. A sloping .front edge onthe front of legs Bil-and 82 cause the latch l8 to cam upwardly as; it strikes the pin .66. and. move ,into locked, position (seeFigs. .2 and 16) as the swivel bracketis swung into engagement .withthe. stern As previously stated, the anti-tilt spring "his designedto extend one and five-eighths inches under a load of one hundred twenty pounds. The engine with which such spring is used is rated at approximately 16 H. P. With this combination the spring will start to elongate and permit rearward and upward tilting of the motor under 'theinfluence of reverse thrust of the v propeller when the engine produces approximately 'jone-th'ird to one-half of its ratedv capacity. Such strength of spring is not critical. Its

strength varies with the rated, horse-power of the engine. With smaller motors the spring does not necessarily have to be weaker. factor is to have the spring elongate and per' mit rearward tilting whenever the engine during reverse thrustof the propeller develops enough power to cause the stern of the boat'to be sucked downwardly if such tilting did not occur. Whenever tilting occurs because the engine is devel oping auangerous amount of reverse thrust, severaleffects take place. The thrust will be in the upward direction and the'stern of the boat will not be sucked down but will be raised instead." If the force of the reverse thrust increases the propeller will work its-way out of the Water. This causes a terrific thrashing and splashing drawing the operators attention thereto. In addition to that the exhaust opening will be out of the water with consequent increase in noise. These occurrences warn the operator of the excessive engine output and the engine can be throttled down until the upward rearward tilt of the motor comes backto normally upright position. 1

While the spring is in an upright position within the recess it need not be so placed to op- The critical.

crate satisfactorily. It is so positioned to save spape'and 'create a 'neat appearance. more any resilient member which develops sub stantially the same force as the spring may be usedin lieu thereof. In the modification shown iii-Figs. '7 to 9, inclusive, the resilient anti-tiit Furthermember. consists or cylindrical rubber membersv I34 and E36 whichare put under torque distor tion by the rearward upward tilting of the out-.

first modification and is of substantially the same construction as that of such modification except that its top I39 has at its forward end anelongatedhollow cylindrical outer bearing, I32. The hollow cylindrical rubber members I34 andISS are mounted within the bearing I32 and havetheirnouter surfaces fixedly secured thereto. inner bearing sleeve I38 passes through theouter bearing .I 32 and its outer surface, is secured to the rubber members I34 and I36.- When the outer. bearing I32 is rotated with respectto the inner bearing sleeve I38,-'the.rubber members: I34 and I38 will be placedunder torque distortion and will resist such turning action.

.;.IThe swivel; bracket I22 is :pivotally mount d said resilient means comprises a rubber-like body having opposed surfaces secured respectively to saidinner and outer bearings.

10. A mounting as claimed in'claim 8 in which said resilient means comprises a coiled tortionaliy loaded spring having one end secured to said inner bearing and the other end secured to said outer bearing. v

e 11. In an outboard motor, mounting means adapted to engage a boat to secure said motor to the boat, a pivotal interconnection between said motor and said means whereby said motor may be tilted rearwardly and upwardly, resilient means acting between said motor and said mounting means, said resilient means being increasingly stressed by continued rearward tilting of said motor to resiliently resist the rearwardupward tilting of said motor, and a latch for disconnecting said resilient means so that continued rearward tiltingof said motor will not increasing- 1y stress said resilient means whereby said motor is free to tilt rearwardly and upwardly, said latch automatically interconnecting said resilient means and said motor as said motor is tilted downwardly and forwardly to its normal position.

RALPH N. KIRCHER. RICHARD C. I-IEIDNE-R. WILFORD B. BURKETT.

References Cited in the-file of this patent UNITED STATES PATENTS 

